Zigzag mechanism for sewing machines



Jan. 22, 1963 R. E. JOHNSON ETAL ZIGZAG MECHANISM FOR SEWING MACHINESFiled Jan. 25, 1960 5 Sheets-Sheet l INVENTORS. Ralph E. Johnson andEdward Koh/mayer ATTORNEY BY WITNESS Jan. 22, 1963 R. E. JOHNSON ETAL3,074,364

ZIGZAG MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 2 Filed Jan. 25,1960 m7 y M W mmm R NS. m EHO VhK w mw 5w 0/ h d WE WITNESS Jan. 22,1963 R. E. JOHNSON ET AL 3,074,364

ZIGZAG MECHANISM FOR SEWING MACHINES Filed Jan. 25, 1960 5 Sheets-Sheet3 INVENTORS. 30 f Ralph E Johnson and y Edward Koh/mayer WITNESS WHWESSJan, 22, 1963 R. E. JOHNSON ETAL 3,074,364

ZIGZAG MECHANISM FOR SEWING MACHINES Filed Jan. 25, 1960 5 Sheets-Sheet4 lllllllllllllllllllllllllllllllllllllllllflllll INVENTORS. Ralph EJohnson and y Edward Koh/mayer M $56M 7 v. aw

/ ATTORNEY Jan. 22, 1963 R. E. JOHNSON EIAL 3,074,364

ZIGZAG MECHANISM FOR SEWING MACHINES 5 Sheets-Sheet 5 Filed Jan. 25,1960 mm WWW mmvm M m h lww R ATTORNEY United States Patent 33374564ZEGZAG MECHANISM iFflR SEWKNG MAQHINES Ralph E. Johnson, Mountainside,and Edward Kohhnayer, Linden, NJ, assignors to The Singer ManufacturingCompany, Elizabeth, N.J., a corporation of New Jersey Filed Jan. 25,19nd, Ser. No. 4,335 4 Claims. (*Ci. 112-458) The present inventionrelates to zigzag or ornamental stitch sewing machines and has for aprimary object to provide a new and improved cam-type actuatingmechanism for imparting lateral vibration to the needle bar.

in any particular ornamental stitch sewing machine the stitch pattern ismade as wide as possible but the maximum width of the stitch pattern islimited to some fixed amount by the characteristics of the machine, forexample, by the fact that the loop taker can accommodate only a certainlateral vibration of the needle and beyond this amount, will notcooperate with the needle. Having determined the maximum lateralvibration of the needle bar, the mechanics of the system determine thedesigned throw of the stitch pattern to obtain a desired lateralposition of the needle. Because of the various limitations on themaximum lateral movement of the needle and on the design limitations onthe mechanics of the system, it is often necessary to provide a separateset of stitch pattern cams for the different ornamental stitch sewingmachines. It is an object of this invention to provide a Zigzagactuating mechanism that is designed to use a set of stitch pattern camsprimarily designed for a different sewing machine and thus render a setof stitch pattern cams universally applicable to various sewingmachines.

Further objects of this invention are to provide a zigzag actuatingmechanism for a sewing machine, which mechanism is economical tomanufacture, is easy to assemble and to adjust, and is efficient,dependable and durable.

Having in mind the above and other objects that will be evident from anunderstanding of this disclosure, the invention comprises the devices,combinations and arrangernents of parts as illustrated in the presentlypreferred embodiment of the invention which is hereinafter set forth insuch detail as to enable those skilled in the art readily to understandthe function, operation, construction and advantages of it when read inconjunction with the accompanying drawings in which:

FIG. 1 is a front elevational view of a sewing machine embodying thepresent invention,

FlG. 2 is a vertical sectional view longitudinally of the sewing machineof FIG. 1,

FIG. 3 is a sectional view taken substantially on the line 3-3 of FIG.2,

FIG. 4 is a top plan view of the bracket arm of the sewing machine ofFIG. 1 with the top cover plate removed,

FIG. 5 is a vertical sectional view taken substantially on the line 55of FIG. 4,

PEG. 6 is a fragmentary detail view of the cam follower mechanism,

FlG. 7 is a fragmentary detail view of the amplitude adjustmentmechanism,

FIG. 8 is a fragmentary sectional view taken substantially on the line3-8 of FIG. 7, and

FIG. 9 is a fragmentary sectional view taken substantially on the line9-9 of FIG. 8.

The present invention is herein illustrated and described as embodied inthe sewing machine forming the subject matter of the copendingapplication of Johnson, Serial No. 4,430, filed Jan. 25, 1960, whereinthe machine is fully disclosed and to which reference may be had for amore complete understanding of the machine.

With reference to the drawings, there is illustrated a sewing machinehaving a frame consisting of a bed 1, a standard 2 rising from one endof the bed and carrying a bracket arm 3 that terminates in .a head 4.Journaled longitudinally of the bracket arm 3 is a main shaft 5 that isdriven through a belt 6 frorn a motor 7 built into the standard 2.

In the head 4, there is a needle bar gate 8 having a pair of verticallyspaced lugs pivotally mounted on a vertical axis pivot rod 1t) carriedby bosses 11. The needle bar gate 8 has a pair of vertically spaced lugs12 in which a needle bar 13 is mounted for endwise reciprocation.Endwise reciprocation is imparted to the needle bar 13 by a crank 14 onthe head end of the main shaft 5 and connected by a link 15 to a collar16 secured on the needle bar.

A needle 17 is secured upon the lower end of the needle bar 13 by aneedle clamp 18. The top of the bed 11 is formed by a bed plate 19, theupper surface of which constitutes the work supporting surface of themachine and which, beneatth the head 1, is provided with the usualthroat plate 20. Upon endwise reciprocation of the needle bar 13, theneedle 17 penetrates work on the throat plate 2% and cooperates with aloop taker 21 in the bed 1 in the formation of lock stitches, andthereby defines the point of stitch formation on the work supportingsurface of the machine.

The loop taker 21 is a vertical axis oscillatory hook having a hook body22 formed with a loop seizing beak 23 and including a depending hookshaft 24 journaled in a bracket 25 in the bed 1. Oscillation is impartedto the hook 21 by a vertical axis shaft 26 journaled in the standard 2and gear connected at its upper end to the main shaft 5. At its lowerend, the shaft 26 carries a crank 27 connected to one end of a pitman 28having its other end connected to one arm 29 of a bell crank leverpivotally mounted on the bracket 25 by a pivot screw 3% The bell cranklever has a second arm 31 connected by a link 32 to a crank 33 securedon the lower end of the hook shaft 24.

Work is advanced across the work supporting surface of the machine. pastthe point of stitch formation by a four-motion feeding mechanismincluding a feed bar 34 pivotally connected at one end to a rocker 35 ona feed advance rock shaft 36 which is oscillated in the usual manner bya pitman 37 actuated by an eccentric 38 on the main shaft 5. Feed liftmotions are imparted to the feed bar 34 by a feed lift shaft 39 havingat one end an arm 49 connected by a link 41 to the feed bar and havingat the other end an arm 42 carrying a cam follower 43 that tracks anaxial displacement cam surface at on the top of the crank 27. The feedlift is biased downwardly to effect lowering of the feed and to hold thecam follower 43 against the cam surface. 44 by a compression spring 45acting between the arm 40 and the bottom of the bed plate 19. The feedbar 34 carries a. feed dog 46 acting on. the work through slots in thethroat plate 2% to advance the work and thereby define the line of feed.The work is held down against the throat plate 20 and the feed dog 46 bya presser foot 47 mounted on the lower end of a presser bar 48 that ismounted for endwise sliding in the head 4 and is biased downwardly by aspring 49.

Upon oscillation of the loop taker 21, the loop seizing beak 23 thereofis moved through an arcuate path of travel. The needle 17, in the usualmanner, is designed to pass adjacent to the path of travel of the beak23 to effect loop seizure. With the needle bar 13 mounted in the gate 8,it is designed to be vibrated laterally of the line of feed so that uponalternate stitches it can descend at different points spaced laterallyof the line of feed,

thereby defining ornamental stitching. To insure that the needle uponalternate stitches will be disposed in loop seizing relation to the beak23, the axis of the pivot rod 10 about which the needle bar13 pivots isarranged coaxially of the hook shaft 24 about which the hook 21oscillates.

A pitman 50 is arranged longitudinally of the bracket arm 3 and ispivotally connected to the needle bar gate 8 by means of a bracket 51secured to the end of the pitman by a screw 52 and pivotally receiving apin 53 secured in the needle bar gate 8; Thus upon endwise movement ofthe pitman 50, oscillation is imparted to the needle bar gate 8, therebyimparting lateral vibration to the needle bar 13.

Mounted in the bracket arm 3 is a vertical axis stud 54 on which isjournalcd a tubular cam shaft 55 having on the lower end thereof a wormwheel 56 which meshes with a worm 57 on the main shaft for impartingrotation to the cam shaft upon rotation of the main shaft. On the upperend of the cam shaft 55, there is mounted a stitch pattern cam 58 havinga peripheral pattern surface 59, which cam is releasably clamped on thecam shaft 55 by a screw 60.

With reference to FIGS. 5 through 9, there is mounted at the rear of thebracket arm a vertically arranged stud 61 which is secured at its lowerend by a screw 62 in a bore 63 in a boss 64 of the bracket arm. Theupper end of the stud 61 is supported by a top cover plate 65 thatcloses the open upper end of the bracket arm 3. Pivotally mounted on thestud 61 is a bracket 66 which is a sheet metal element consisting of avertical body portion 67 having bent therefrom at right angles at itstop and bottom, cars 68 and 69, which ears are provided with apertures70 and 71 that slidably receive the stud 61. The bracket 66'ispositioned vertically on the stud 61 by a sleeve 72 resting on anaccurately machined surface 73 on the top of the boss 64 and having anaccurately machined upper surface 74 on which the bracket 66 rests.

At a point spaced from the stud 61, the ears 68 and 69 of the bracket 66are provided with apertures 75 and 76 that slidably receive a pivot pin77. The pin 77 is held against endwise movement by a locking plate 78lying on the top of the ear 68 of the bracket 66. The plate 78 has arearward end that is bifurcated to provide a slot 79 that slidablyreceives the reduced portion of thestud 6-1 formed by a groove 80.Extending inwardly from the one edge of the plate 78, FIG. 6, there is aslot 81. The pin 77 has a groove 82 defining a reduced diameter portionthat is slidably received within the slot 81. A screw 83 extends throughthe plate 78 and is threaded into the ear 68 to lock the plate 78 andthus lock the pin 77 in position.

Pivotally mounted on the pin 77 is an oscillating element in the form ofa U-shaped plate 84 formed of sheet metal and arranged generallytransversely of the bracket arm 3. The plate 84 is cut away, as at 85,to accommodate the main shaft 5 and the worm 57, thereby defining a baseportion 86 and rearwardly extending arms 87 and 88 disposed respectivelyabove and below the main shaft 5. The upper arm 87 is bent to form anear 89 disposed in spaced relation above the upper ear 68 of the bracket66 and having an aperture slidably receiving the pin 77. The lower arm88 is bent to form an car 90 having an aperture slidably receiving thepin 77. The sleeve 72 is provided with a flange 91 having an accuratelymachined upper surface on which the ear 90 rests for positioning theplate 84 vertically. For rigidity, the base portion 86 of the plate 84is provided with a laterally bent stiffening rib 92.

There is provided a cam follower 93 formed of sheet metal and pivotallymounted by means of a pivot screw 94 on an ear 9S bent from the top ofthe plate 84. At the forward end of the follower 93 there is anupstanding follower element 96 that is adapted to cooperate with theperipheral cam surface 59 of the stitch pattern cam 58. The rearward endof the follower 93 is bifurcated to provide a slot 97 that receives areduced diameter portion 98 of the stud 61 to support the rear end ofthe cam follower against movement endwise of the stud 61 and to providea sliding pivot for the same.

In the lower arm 83 of the plate 84 there is provided a slot 99 throughwhich extends the one end of the pitman 50. On that side of the plate 84opposite from the needle bar gate 8, there is mounted on the end of thepitman 50 a block 100 secured thereon by a screw 101.

The needle bar gate 8 is biased in a counterclockwise direction aboutthe axis of the pivot rod 10 by a torsion spring 102 coiled about thepivot rod 10 between the bearing lugs 9. The one end of the spring 102bears against the needle bar gate 8 and the opposite end is anchored ina collar 103 secured by a set screw 104 on the pivot rod 10. The collar103 abuts against the top of the bottom one of the bearing lugs 9 andtogether with a head 105 of the pivot rod 10 serves to prevent end playof the pivot rod 10. The bias of the spring 102 tends to pull the pitmanto the left as seen in FIG. 7.

The bracket 66 determines the center adjustment of the ornamental stitchpattern by varying the position of the pivot pin 77 which defines thepivot axis for the plate 84. Adjustment of the bracket 66 is provided bya handle 106 secured to the locking plate 78 by rivets 107. The handle106 extends through a slot 108 in the front wall of the bracket arm 3and through a slot 109 in a decorative indicia plate 110 secured byscrews 111 on the front wall of the bracket arm. The plate 110 isprovided with the letters L,".C and R, FIG. 1, to indicate the left,center, and right settings of the center adjustment. The plate 78 isformed of spring steel and acts to bias the handle 106 upwardly to seatthe same in notches 112 at the various settings. To release the handle106 from the notches 112, it is depressed against the spring action ofthe locking plate 7 8.

The spring 102 acts to exert a pull on the pitman 50 which, through theblock 100, biases the plate 84 in a clockwise direction, as seen in FIG.7, about the axis of the pivot pin 77. The plate 84, through the pivotscrew 94, biases the cam follower 93 about its pivot axis defined by thestud 61 to engage the follower element 96 against the peripheral patternsurface 59 of the stitch pattern cam 58. Upon rotation of the stitchpattern cam 58, oscillation is imparted to the cam follower 93, thefollower being moved in one direction by the pattern surface 58 and inthe other direction by the spring 102. Through the pivot screw 94,oscillation of the cam follower 93 oscillates theplate 84 about the axisof the pivot pin 77. Through engagement of the plate 84 and the block100, as the plate 84 is oscillated, the pitman 50 is pulled to theright, FIG. 7, in opposition to the spring 102 and is released formovement to the left under the action of the spring 102. Endwisemovement of the pitman 50 imparts lateral vibration to the needle bargate- 8. V

The amplitude of the endwise movement imparted to the pitman 50 and thusthe lateral vibration of the needle bar, depends upon the setting of theblock 100 radially relatively to the pivot axis of the plate 84. To varythe amplitude, the pitman 50 is adapted to be moved pivotally about theaxis of the pin 53 to move the opposite end thereof along the slot 99 toposition the block 100 between a maximum setting and a zero settingradially of the pivot pin 77. For this purpose, there is provided azigzag amplitude adjustment lever 113 of the bellcrank type pivotallymounted by means of a shoulder screw 114, FIG. 5, on the lower end ofthe stud S4. The lever 113 consists of an intermediate portion 115formed of spring steel and a handle portion 116 secured thereto byrivets 117. The handle portion 116 extends through a slot 118 in thefront wall of the bracket arm 3 and through a slot 119 in a decorativeindicia plate 120 secured by screws 121, FIG. 1, to the front wall ofthe bracket arm 3 and having numerals to indicate the setting of thezigzag amplitude. biases the handle portion 116 against the upper edgeof the slot 119 to hold the lever 113 frictionally in its adjustedposition. At its other end, the lever 113 carries 'a' block 122 securedto the spring portion 115 by a rivet 123 and by a screw 124 extendingthrough the spring portion 115 and threaded into the block 122. The headof the screw is disposed in a slot 125 in the pitman 50 so that uponpivotal movement of the lever 113, the pitman 50 is pivotally moved toshift the block 100 along the slot 99.

The block 100 is formed generally cylindrical to provide a line contacton the plate 84 and it is provided with a slabbed face 126 on the sideadjacent to the stud 61 to provide clearance relatively to the sleeve72. At the zero setting of the zigzag amplitude adjustment, the end ofthe pitman Si) is disposed with the axis of the block 100 coaxialrelatively to the pin '77. To determine this setting, the handle portion116 abuts against the end 127 of the slot 119 in the plate 12% On thetop of the block 160, there is provided an upstanding lug 128 having acam face 129 that is adapted to engage the lower end of the pivot pin77, as seen in FIGS. 8 and 9, when the zigzag amplitude is adjusted tozero for straight stitching. The cam face 129 retracts the pitman 50against the action of the spring 162 and lifts the block 100 out ofengagement with the plate 84, the plate 84 being provided with acut-away 1341 to insure clearance between the plate 84 and the block 100when at the zero amplitude setting. Thus, at the zero setting of thezigzag amplitude adjustment, any pivotal movement of the plate 84 willnot impart any movement to the pitman 50 and the needle bar gate 3 isheld in a straight stitching positi n by the spring 102 that biases thesame into a stop position determined by the engagement of the cam face129 against the pivot pin 77. At the same time, the bias of the spring182 is completely removed from the plate 84 and thus from the camfollower 93 so that the follower element 96 will not track the camsurface 59, thereby eliminating unnecessary wear on the cam 5-8 duringstraight stitching.

At the maximum zigzag amplitude setting, the end of the pitman 50 ispositioned with the axis of the block 100 disposed coaxially with theaxis of the pivot screw 94. To position the mechanism accurately at themaximum zigzag amplitude setting and also as a gauge surface forassembly adjustment of the machine, the pitman 50 has an accuratelymachined face 131, FIG. 7, that is adapted to abut against the peripheryof the stud 54. Thereafter, the plate 120 is mounted with the end of theslot 119 opposite from the end 127 engaging the handle portion 116,thereby locating the end 127 to determine the minimum setting.

The zigzag amplitude adjustment provided by the lever 113 is designed tovary the lateral vibration of the needle from zero, which is forstraight stitching, and a maximum which in the present machine isapproximately 0.160 inch (4 mm.). The two extreme positions at themaximum zigzag amplitude setting define the side edges of the zigzagfield. The zigzag field or centering adjustment varies the straightstitching position when the amplitude adjustment is at zero, that is,the line of stitching will be placed in the center or along one of theside edges of the zigzag field. It also determines the position of thezigzag pattern within the field, that is, with the field adjustment atthe center position, the lateral vibrations of the needle will be anequal distance upon each side of the center line of the field and, withthe field adjustment at either the right or left positions, the lateralvibrations of the needle will be from either the right or left sideedges of the zigzag field so that the one side of the pattern will bealong one side edge of the field.

Upon actuation of the zigzag mechanism, the plate 84 pivots about thepin 77. Upon adjustment of the zigzag The spring portion 115 6. field bymeans of the' handle 106, the plate 84 pivots about the axis of theconnecting or driving. screw 94 for the plate 84. To obtain thedesiredcontrol of the zigzag amplitude and field, the displacement ofthe pin 77 by the field adjustment mechanism must be equal to thedisplacement of the screw 94 by the actuating mechanism. With thedisclosed construction, it will be seen. that by the use of the camfollower 94, that is separate from the plate 34, the displacement of thescrew 94 is lessthan the total throw of the cam 58. In this manner,there can be used cams which have a maximum throw that is greater thanthat which is designed for the particular machine, and which at the sametime, will maintain the necessary condition that the displacement of thescrew 94 and pin 77 be equal. The advantage of this is that camsprimarily designed for a different machine can be used, thus making thecams universal.

The assembly of the present zigzag mechanism into the machine is alsovery simple. After the stud 61 is inserted, the sleeve 72 and bracket 66are placed on it. Then, with the pitman 50 and the lever 113 assembled,the plate 84 with the cam follower 93 mounted thereon, is inserted,being careful to place the end of the pitman into the slot 99 and toinsert the end of the cam follower 93 into the groove 98. The pin 77 isthen inserted and locked by the plate 78, the plate being inserted withthe stud 61 in the slot 7d and the pin 7'7 in the slot 81. The screw 83is then inserted to lock the assembly.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates to a preferred embodiment of ourinvention which is for purposes of illustration only and not to beconstrued as a limitation of the invention. All such modifications whichdo not depart from the spirit of the invention are intended to beincluded within the scope of the appended claims.

Having thus set forth the nature of the invention, what we claim hereinis:

1. In a zigzag sewing machine having a frame, a needle bar, means formounting said needle bar in said frame for endwise reciprocation and forlateral vibration, and means for imparting lateral vibration to saidneedle bar comprising a bracket, a pivot element pivotally mounting saidbracket in said frame, an oscillating element, means for pivotallymounting said oscillating element on said bracket on a pivot axisparallel to and spaced from the pivot axis of said bracket, a pitman,means pivotally connecting said pitman to said needle bar, meansadjustably connecting said pitman to said oscillating element foradjustment outwardly relatively to the pivot axis of said oscillatingelement, and means for imparting oscillation to said oscillating elementcomprising a rotary cam journaled in said frame, a cam followerslidingly pivoted on said pivot element and operatively engaging saidcam, and means pivotally interconnecting said cam follower and saidoscillating element at a point spaced from the pivot axis of saidoscillating element for pivotally securing said cam follower and saidoscillating element together at said point for unitary oscillation aboutthe axis of said oscillating element.

2. In a zigzag sewing machine comprising a frame, a needle bar, meansmounting said needle bar in said frame for endwise reciprocation and forlateral vibration, and means for imparting lateral vibration to saidneedle bar comprising a stud mounted at one end in said frame, a bracketpivotally mounted on said stud, a pivot pin loosely mounted in saidbracket on an axis in spaced parallel relation to the axis of said stud,an oscillating element loosely mounted on said pivot pin foroscillation, said stud and said pivot pin having peripheral grooves, alocking plate having a bifurcated end defining a slot cooperating withthe groove in said stud and a slot extending inwardly from the edgethereof and cooperating with the groove in said pivot pin to hold saidbracket on said stud and to hold said pivot pin against endwise movement, means for securing said locking plate to said bracket at a pointspaced from said slots, a 'pitman, means pivotally connecting saidpitman to said needle bar, means adjustably connecting said pitman tosaid oscillating element for adjustment outwardly relatively to thepivot axis of said oscillating element, and means for impartingoscillation to said oscillating element.

3. In a zigzag sewing machine comprising a frame, a needle bar, meansmounting said needle bar in said frame for endwise reciprocation and forlateral vibration, and means for imparting lateral vibration to saidneedle bar comprising a stud mounted at one end in said frame, a sleevemounted on said stud, a bracket pivotally mounted on said stud andpositioned endwise of said stud by said.

sleeve, a pivot pin loosely mounted in said bracket on an axis in spacedparallel relation to the axis of said stud, an oscillating elementloosely mounted on said pivot pin for oscillation, a flange on saidsleeve and engaged by said oscillating element for positioning the sameendwise of said stud, said stud and said pivot pin having peripheralgrooves, a locking plate having a slot cooperating with the groove insaid stud and a slot cooperating with the groove in said pivot pin tohold said bracket on said stud and to hold said pivot pin againstendwise movement, a pitman, means pivotally connecting said pitman tosaid needle bar, means adjustably connecting said pitman to saidoscillating element for adjustment outwardly relatively to the pivotaxis of said oscillating element, and means for imparting oscillation tosaid oscillating element.

4. In a zigzag sewing machine having a frame, a needle bar, means formounting said needle bar in said frame for endwise reciprocation and forlateral vibration, and means for imparting lateral vibration to saidneedle bar comprising an oscillating element, means for pivotallymounting said oscillating element in said frame and de fining a pivotaxis for the same, a pitrnan, means connect- 8'. ing said pitman to saidneedle bar for imparting lateral Vibration to said needle bar uponendwise movement of said pitman, means defining an adjustable connectionbetween said pitman and said oscillating element for imparting endwisemovement to said pitman upon oscillation of said oscillating element andfor varying the connection outwardly relatively to the pivot axis ofsaid oscillating element between a maximum position and a minimumposition, and means for imparting oscillation to said oscillatingelement comprising a rotary cam journaled in said frame and operativelyengaging said cam, a cam follower element, means for pivotally securingsaid cam follower element to said oscillating element at a point spacedfrom the pivot axis of said oscillating element for relative pivotalmovement about an axis parallel to the pivot axis of said oscillatingelement and for unitary oscillation of said oscillating element and saidcam follower element at said point about the pivot axis of saidoscillating element, and means for slidingly pivoting said cam followerin said frame on an axis parallel to and remote from the pivot axis ofsaid oscillating element and the pivot axis of the means interconnectingsaid cam follower element and said oscillating element.

References Cited in the file of this patent UNITED STATES PATENTS976,664 Laubenstein Nov. 22, 1910 2,684,649 Scarpa July 27, 19542,757,626 Fujita Aug. 7, 1956 2,832,302 Gegauf Apr. 29, 1958 2,833,233DAmico May 6, 1958 2,905,119 Bono Sept. 22, 1959 2,972,319 Moro Feb. 21,1961 FOREIGN PATENTS 27,253 Great Britain of 1896 517,363 Italy Feb. 28,1955 792,784 Great Britain Apr. 2, 1958

1. IN A ZIGZAG SEWING MACHINE HAVING A FRAME, A NEEDLE BAR, MEANS FORMOUNTING SAID NEEDLE BAR IN SAID FRAME FOR ENDWISE RECIPROCATION AND FORLATERAL VIBRATION, AND MEANS FOR IMPARTING LATERAL VIBRATION TO SAIDNEEDLE BAR COMPRISING A BRACKET, A PIVOT ELEMENT PIVOTALLY MOUNTING SAIDBRACKET IN SAID FRAME, AN OSCILLATING ELEMENT, MEANS FOR PIVOTALLYMOUNTING SAID OSCILLATING ELEMENT ON SAID BRACKET ON A PIVOT AXISPARALLEL TO AND SPACED FROM THE PIVOT AXIS OF SAID BRACKET, A PITMAN,MEANS PIVOTALLY CONNECTING SAID PITMAN TO SAID NEEDLE BAR, MEANSADJUSTABLY CONNECTING SAID PITMAN TO SAID OSCILLATING ELEMENT FORADJUSTMENT OUTWARDLY RELATIVELY TO THE PIVOT AXIS OF SAID OSCILLATINGELEMENT, AND MEANS FOR IMPARTING OSCILLATION TO SAID OSCILLATING ELEMENTCOMPRISING A ROTARY CAM JOURNALED IN SAID FRAME, A CAM FOLLOWERSLIDINGLY PIVOTED ON SAID PIVOT ELEMENT AND OPERATIVELY ENGAGING SAIDCAM, AND MEANS PIVOTALLY INTERCONNECTING SAID CAM FOLLOWER AND SAIDOSCILLATING ELEMENT AT A POINT SPACED FROM THE PIVOT AXIS OF SAIDOSCILLATING ELEMENT FOR PIVOTALLY SECURING SAID CAM FOLLOWER AND SAIDOSCILLATING ELEMENT TOGETHER AT SAID POINT FOR UNITARY OSCILLATION ABOUTTHE AXIS OF SAID OSCILLATING ELEMENT.